Review Questions
1. Which of the following is the most serious type of redo log file
failure?
A. The loss of an entire redo log file group, but no loss in any other
group
B. The loss of one member of each redo log file group
C. The failure of the ARC0 background process
D. The failure of the LGWR background process
---
Ans: A.
Loss of an entire redo log file group can result in loss of committed
transactions that may not
yet have been written to the database files. Losing all members of a
redo log file group except
for one does not affect database operation and does not result in data
lost. A message is placed
in the alert log file. The failure of LGWR or ARC0 causes an instance
failure, but you do not lose
any committed transaction data.
2. Which of the following tools or options does not ensure that either
no committed transactions
are lost or the MTBF is minimized?
A. Streams
B. Real Application Clusters
C. LogMiner
D. Archived redo logs
E. Standby databases
---
Ans: C.
The LogMiner tool helps you see which transactions have occurred in the
database along
with the DML to reverse the changes, but it does not minimize the MTBF
or reduce the possibility
of committed transaction loss.
3. When the database is in ARCHIVELOG mode, database recovery is
possible up to which event or time?
A. The last redo log file switch
B. The last checkpoint position
C. The last commit
D. The last incremental backup using RMAN
---
Ans: C.
In ARCHIVELOG mode, recovery of the database is possible up to the last
COMMIT statement;
in other words, no uncommitted transactions are lost in ARCHIVELOG mode.
4. From the following, select the true statement regarding image copies
and backup sets.
A. An image copy stores one datafile per image copy, and a backup set
can store all datafiles
in a single file.
B. An image copy stores one datafile per image copy, and a backup set
consists of one file per
datafile backed up.
C. Both image copies and backup sets use a single file to store all
objects to be backed up.
D. A backup set stores each datafile in its own backup file, but an
image copy places all datafiles
into a single output file.
--
Ans: A.
In addition to storing multiple datafiles in a single output file,
backup sets do not contain
unused blocks and can be compressed.
5. The option on the EM Database Control backup scheduling options
screen that allows you to
refresh an image copy on disk with an incremental backup is known as
which new RMAN feature?
A. Incrementally updated backups
B. Incremental level 0 backups
C. Compressed image copy refresh
D. Compressed incremental backups
---
Ans: A.
Incrementally updated backups save time during a recovery operation
because fewer incremental
backups need to be applied to the restored image copy.
6. When should the DBA make a trace copy of the control file using ALTER
DATABASE BACKUP
CONTROLFILE TO TRACE?
A. After every backup
B. After multiplexing the control files
C. Whenever restarting the instance
D. Whenever the physical structure of the database changes
---
Ans: D.
In the rare event that all multiplexed copies of the control file are
lost, having a trace copy
of the control file reduces the possibility of data loss and reduces
downtime during a recovery
operation.
7. Which of the following is not a step in configuring your database to
archive redo log files?
A. Place the database in ARCHIVELOG mode.
B. Multiplex the online redo log files.
C. Specify a destination for archived redo log files.
D. Specify a naming convention for your archived redo log files.
---
Ans: B.
Although it is recommended that you multiplex your online redo log
files, setting up the archival
of your redo log files is not required.
8. Why are online backups known as inconsistent backups?
A. Because not all control files are synchronized to the same SCN until
the database is shut down
B. Because both committed and uncommitted transactions are included in a
backup when the
database is online
C. Because a database failure while an online backup is in progress can
leave the database in an
inconsistent state
D. Because online backups make copies of datafiles while they are not
consistent with the
control files
---
Ans: D.
During an online backup, even if all datafiles are backed up at the same
time, they are rarely,
if ever, in synch with the control file.
9. In the Disk Settings section of the EM Database Control Configure
Backup Settings page, which
of the following backup settings is not configurable?
A. Disk Backup Type
B. Control File Autobackup Format
C. Disk Backup Location
D. Parallelism
---
Ans: B.
Settings such as the control file autobackup filename format and the
snapshot control file destination
filename must be configured using the RMAN command-line interface.
10. Which of the following initialization parameters specifies the
location where the control file
trace backup is sent?
A. USER_DUMP_DEST
B. BACKGROUND_DUMP_DEST
C. LOG_ARCHIVE_DEST
D. CORE_DUMP_DEST
---
Ans: A.
The trace backup is created in the location specified by USER_DUMP_DEST,
and its format is
sid_ora_pid.trc.
11. Which of the following pieces of information is not available in the
control file?
A. Instance name
B. Database name
C. Tablespace names
D. Log sequence number
---
Ans: A.
The instance name is not in the control file. The control file has
information about the physical
database structure.
12. Which data dictionary view shows that the database is in ARCHIVELOG
mode?
A. V$INSTANCE
B. V$LOG
C. V$DATABASE
D. V$THREAD
---
Ans: C.
The V$DATABASE view shows whether the database is in ARCHIVELOG mode or
in
NOARCHIVELOG mode.
13. Which file records all changes made to the database and is used only
when recovering
an instance?
A. Archive log file
B. Redo log file
C. Control file
D. Alert log file
---
Ans: B.
The redo log file records all changes made to the database. The LGWR
process writes the redo
log buffer entries to the redo log files. These entries are used to roll
forward, or to update, the datafiles
during an instance recovery. Archive log files are used for media
recovery.
14. Which initialization parameter contains the value used as the
default for archived log file
destination 10?
A. LOG_ARCHIVE_DEST
B. STANDBY_ARCHIVE_DEST
C. LOG_ARCHIVE_DUPLEX_DEST
D. DB_RECOVERY_FILE_DEST
E. USE_DB_RECOVERY_FILE_DEST
---
Ans D.
DB_RECOVERY_FILE_DEST points to the Flash Recovery area, and this is the
default for
archived log file destination number 10.
15. Which of the following commands is a key step in multiplexing
control files using an SPFILE?
A. ALTER SYSTEM SET CONTROL_FILES= '/u01/oradata/PRD/cntrl01.ctl',
'/u01/
oradata/PRD/cntrl02.ctl' SCOPE=SPFILE;
B. ALTER SYSTEM SET CONTROL_FILES= '/u01/oradata/PRD/cntrl01.ctl',
'/u01/
oradata/PRD/cntrl02.ctl' SCOPE=MEMORY;
C. ALTER SYSTEM SET CONTROL_FILES= '/u01/oradata/PRD/cntrl01.ctl',
'/u01/
oradata/PRD/cntrl02.ctl' SCOPE=BOTH;
D. The number of control files is fixed when the database is created.
---
Ans: A.
The location of the new control files is not valid until an operating
system copy is made of the current
control file to the new location(s) and the instance is restarted. The
SCOPE=SPFILE option specifies
that the parameter change will not take place until a restart.
Specifying either MEMORY or BOTH
causes an error, because the new control file does not yet exist.
16. Which statement adds a member /logs/redo22.log to redo log file
group 2?
A. ALTER DATABASE ADD LOGFILE '/logs/redo22.log' TO GROUP 2;
B. ALTER DATABASE ADD LOGFILE MEMBER '/logs/redo22.log' TO GROUP 2;
C. ALTER DATABASE ADD MEMBER '/logs/redo22.log' TO GROUP 2;
D. ALTER DATABASE ADD LOGFILE '/logs/redo22.log';
---
Ans: B.
When adding log file members, specify the group number, or specify all
the existing group
members.
17. What is the biggest advantage of having the control files on
different disks?
A. Database performance.
B. Guards against failure.
C. Faster archiving.
D. Writes are concurrent, so having control files on different disks
speeds up control
---
Ans: B.
Having the control files on different disks ensures that even if you
lose one disk, you lose only
one control file. If you lose one of the control files, you can shut
down the database, copy a control
file, or change the CONTROL_FILES parameter and restart the database.
18. To place the database into ARCHIVELOG mode, in which state must you
start the database?
A. MOUNT
B. NOMOUNT
C. OPEN
D. SHUTDOWN
E. Any of the above
---
Ans: A.
To put the database into ARCHIVELOG mode, the database must be in the
MOUNT state; the control
files and all datafiles that are not offline must be available to change
the database to
ARCHIVELOG mode.
19. Which of the following commands places the database in ARCHIVELOG
mode?
A. ALTER SYSTEM ARCHIVELOG;
B. ALTER DATABASE ARCHIVELOG;
C. ALTER SYSTEM SET ARCHIVELOG=TRUE;
D. ALTER DATABASE ENABLE ARCHIVELOG MODE;
E. ALTER DATABASE ARCHIVELOG MODE;
---
Ans: B.
You use the ALTER DATABASE ARCHIVELOG command while the database is in
the MOUNT state
to enable archiving of online redo log files.
20. Which of the following substitution variables formats are always
required for specifying the
names of the archived redo log files? (Choose all that apply.)
A. %d
B. %s
C. %r
D. %t
---
Ans: B, C, D.
The substitution variable %d, which represents the database ID, is
required only if multiple
databases share the same archive log destination.
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